One type of fire control mechanism commonly used in semiautomatic handguns includes a hammer that is pivotable from a rearward cocked position to a forward position for impacting a firing pin. A sear releasably retains the hammer in the cocked position via a spring maintained in compression. When the trigger is moved, the sear is moved to release the hammer, which moves in response to the release of the stored energy in the spring, thereby allowing the hammer to strike the firing pin which in turn is driven forward to fire a chambered cartridge.
Another common fire control mechanism utilizes a striker-type firing pin. In handguns employing the striker-type firing pin, the trigger is connected to a trigger bar. Movement of the trigger causes movement of the trigger bar, which in turn (in certain embodiments) causes a sear to rotate about a pivot point. Upon rotation of the sear, a spring is compressed and an upper portion of the sear is displaced relative to the firing pin. Upon displacing the sear a sufficient distance to clear a depending leg of the firing pin, the firing pin is urged forward by a spring and strikes the rear of the cartridge, thereby discharging the firearm.
In either configuration (the pivotable hammer or the striker-type), the sear is an elongated element that is rotatable about a pivot point located substantially at one end thereof. By locating the pivot point at one end, the elongated element can be fairly easily rotated about the pivot point. In particular, because a substantial portion of the mass of the elongated element is located at one point distal from the pivot point, there is a tendency for the elongated element to rotate about the pivot point.